your oil pressure will come down as your oil gets a little older. the viscosity modifiers begin to break down and the oil becomes thinner. it's funny my car gets 20psi at idle with brand new fresh oil in there after it is up to operating temps. after 1500 miles the same oil is at 14psi at idle...
you prolly won't be able to tighten the bolts if they are the original ones. The front ones will really not budge.
Best bet would be 2 recall kits and a set of AL SFB's to lock that subframe down tight. PM me and I can help you out.
Buy the lisle tool for replacing taking valve springs out. I have it and it makes the replacement of seals on a SHO about a 1 to 1.5 min per valve. Just have to be careful as the tool is almost the same size as the hole for the bucket.
Use that and get one of the air things to pressurize the...